It's well documented that a woman's pay is often less than a man's—even for the same work. But research finds such wage discrimination infectious: Managers who work with more females, either as subordinates or peers, earn less than those who work with mostly men, according to a survey of some 500 companies.
"This is a hidden phenomenon that affects both men and women managers," says Cheri Ostroff of Columbia University in New York. A similar trend occurs when workers' average age veers above or below age 40.
Ostroff found pay discrepancies across a wide range of industries from engineering firms to advertising companies. On average, managerial pay decreases approximately $500 for each 10-percent increase of women in the office. The salary for managing a group of only women was $9,000 less than managing a team equally divided by gender.
